Why Are Worms Escaping My Bin?

Nothing concerns a new worm bin owner more than when they see worms crawling up the sides of the worm bin, leaving them to wonder what they did wrong to cause this.

Unzipping the lid of your Urban Worm Bag or opening the top of your Hungry Bin to see what appears to be an escape attempt does bad things to a new worm parent’s psyche.

The good news is that worms on the walls are not necessarily a sign you’re doing something wrong.

This article will explain 4 reasons why worms will crawl up the sides of your worm bin.

This article is part of a “Vermicomposting 101” series of posts aimed at helping the beginning vermicomposter. To read other “VC101” articles on how to start a worm bin, how to choose worm food, how to maintain moisture, and the differences between composting and vermicomposting, please visit the Vermicomposting 101 section of this site!

Why Are Worms Crawling on the Walls of My Bin?

1) Worms Really Are Trying to Escape

Worms escaping a Can O' Worms

First, the bad news.

The worms may really be trying to get the heck out of Dodge.

But a mass escape attempt will look different than dozens of wandering worms. When worms get stressed and/or near death, you will often see them bunched up with one another.

Now, I’m not talking dozens. I’m talking hundreds or thousands of them.

If they are unhappy, you will see them gather near the opening of the bin, where the air is the freshest and coolest, all trying to escape at once.

Why is this happening? This is likely due to a lack of ventilation, overheating, or a chemical nature of the vermicompost that has become noxious to the worms. If the pictures you’ve seen so far don’t jive with what you’re seeing in your bin, then read on.

The news gets better!

2) Worms Are Attracted to Condensation

Worms crawling on walls of bin

By far, the most common reason to see worms on the walls and underside of the lid of your worm bin is because condensation is present.

Condensation occurs when warm air comes into contact with cool surfaces.

The air above your vermicompost, thanks to the heat-generating worms and microbes below, will often be warmer than the interior surfaces of your worm bin. When this warm humid air comes into contact with cold plastic or other surfaces, droplets will cover the inside of your bin.

Water is catnip for worms. And while you’d think that worms would be happier in a moist vermicompost full of food, don’t be surprised to see them happily wallowing in these droplets.

But the thing is, only some of them are going to do this.

So if the inside of your bin is wet, due to a recent feeding or a misting of your vermicompost, and you see a few dozen worms crawling up the sides, leaving their castings in their wake?

It’s normal and there’s nothing to worry about. I see this in both my Urban Worm Bags and with my Michigan SoilWorks CFT during the times of the year when we cover it to trap heat and moisture.

3) Worms May Be Reacting to Vibration

One of Charles Darwin’s observations about worms is that they are indifferent to sound, but can be highly agitated by vibration.

Utility rooms, which are common places to keep a worm bin, often have washers and dryers which will produce a constant vibration, lasting 45 minutes or more. You may find that worms will not be thrilled when your out-of-balance Kenmore washer hits the spin cycle. You can expect to see a less-than-peaceful worm bin.

Air handlers for central air conditions or window air conditioners can also produce a constant, but low-level vibration which can make the worms go a little nutty too.

4) Indian Blue Worms Are Reacting to Changes in Barometric Pressure

This next one is a little tricky.

If you notice that your red wigglers begin crawling the walls by the dozens or worse when a thunderstorm approaches, then your Red Wigglers may actually be Indian Blues. Although the perionyx excavatus Indian Blues are not that closely related to the eisenia fetida “Reds,” the two species are often confused.

Skinnier than the already-scrawny Red Wigglers, Blues can be identified by the tough-to-see clitellum which is flush to the body of adult and much closer to its head. Red Wigglers feature a fleshier, raised clitellum, distinct banding, and a yellow-tipped tail.

Now don’t get me wrong; Blues are excellent vermicomposters. But there is something about the onset of a thunderstorm that can make these worms get a little flighty and try to leave the nest. You know how your Aunt Millie’s arthritic knees tell her that a thunderstorm is about to hit?

Well a bin full of Indian Blues might become a bin half full of Indian Blues when the barometric pressure drops before a storm.

It is unfortunately very common for a shipment of Red Wigglers to be at least partially Indian Blues. And to be frank, because Blues are excellent composting worms, most vermicomposters are happily unaware that they’ve got them. But if this is an issue OR somebody wants to culture red wigglers for sale, it can be maddening to learn that you’ve got the Blues, literally.

How to Prevent Worms from Crawling on the Walls

If worm climbing the walls is just unacceptable to you, there are a few ways to prevent it.

Keep Your Bin Less Moist with Lots of Dry Bedding

The food waste you’re likely using in your bin is going to feature a much  higher water content than you’ll want your worm bin to have.

So to keep the moisture content within a reasonable range (60%-80%), you’ll want to add dry bedding to your feedings to help sop up that excess moisture.

Read this article for more information on excellent choices for worm bedding.

Keep the lid open

Because you can equalize the temperature and humidity by keeping the lid or cover open, this is the most effective way to prevent the condensation that will attract the worms. In fact, worms are unable to climb walls that are completely dry as they would dehydrate quickly and wouldn’t make it that far.

Keep a Bright Light Above the Bin

This is a common worm bin startup tactic when worms are not yet acclimated to their surroundings, but it works well with a mature bin too. Worms find bright light repellent and will choose to remain in the vermicompost rather than venture out into the light. Whether you’re using an Urban Worm Bag, a Hungry Bin, or a Rubbermaid bin, one of those clamp lights shining down into the worm compost will do the trick!

Summary: Worms on the Walls is Probably No Disaster

Unless we’re talking thousands of worms trying to flee your bin at once, worms on the walls of your bin are likely no big deal. And if you’re using an enclosed bin, then I’d bet dollars to donuts that simple condensation is the likely cause.

If you’ve got worms on the walls and lid and you’re it’s something worse, feel free to e-mail me at steve@urbanwormcompany or post your comment below!

22 thoughts on “Why Are Worms Escaping My Bin?

  1. I have a similar issue, except the worms are bunching up and trying to escape through the bottom of my Urban Worm Bin v2. I opened up the bottom and found a lot of worms between the zipper and the cinch. I’m trying a few different things, but what would cause this?


    1. Hi Lisa,
      Worms are attracted to moisture so if you’ve noticed leachate collecting at the bottom of your UWB, chances are you’ve got worms there too. Over time, as your Bag fills up and the moisture equalizes, you should see this problem subside. Just make sure to keep adding dry bedding in the form of paper and cardboard to sop up the moisture released by your decomposing food waste.


  2. Hi Steve,

    Thank you for the article. I don’t mind the adult worms climbing the walls of my bin, but the little guys that are almost too small to see hanging onto the lid of the bin. I worry that when I open the lid for feeding, the walls dry out, trapping and killing some of the babies outside of the bin’s bedding. On several occasions I’ve spent 15-20 minutes gently trying to save the babies, but this is very time consuming and it is difficult being so gentle. Should I be concerned about the young worms or just keep feeding them and hope enough are lucky enough to stay in the bedding to replenish numbers, or hopefully grow? Thank you for your time and all your help.


    1. I use a little paint brush on my bin. It has been rainy here the past few days and I’ve had quite a few escape and die😔

      1. How about using a gentle spray from a spray bottle filled with rainwater or water left to off-gas the chlorine for 24hr or so?

    2. I’m doing this every other day now. All babies! How do they get up there? Are the adults laying their cocoons on the rough edges of the holes?

  3. 1. When is the best time to add ENC’s to outdoor garden (Idaho). Cover crop coming in and will be adding tons of leaf litter.
    2. We live in a large forest, is adding ENC’s a bad idea? Wanting them for their tunneling.


  4. I just introduced my worms to the worm bin earlier this week, and I can’t really tell whether they’re trying to escape or not. The bin is starting to smell however, so I’m guessing something is off with the bin. Should I remove any food scraps that are in there and start again?

    1. I am also having this problem. I hope we can get an answer. Sadly, I usually don’t find them til they’ve died and this is simply unacceptable!

  5. I just added more worms (I think Red wigglers and some blues) into my bin (hungry bin) that is running hot due to me living in Texas. Both seem to be bunching up on the sides but I don’t think any of the original worms are trying to get out. Can it be that they are used to cooler temperatures where as the older worms experienced a gradual increase in temperature? I am trying various ways to cool it down for them.

    1. Hi Timothy,
      I doubt it. I think that you’ll find that in a bin where you have condensation on the inside your bin (like with the Hungry Bin or UWB) that you’ll always have wanderers! 🙂

  6. How about using a gentle spray from a spray bottle filled with rainwater or water left to off-gas the chlorine for 24hr or so?

  7. Hi Steve,

    I have a problem with lots of worms escaping through the bottom of the bag. They are crawling up the walls (mainly in the night) as well but not in the manner of a mass exodus/bunched together so this doesn‘t really concern me. I am confused about the moisture level in my bag. As recommended I used Coco Coir as bedding medium. I let this sit in the bag overnight with the excess water draining out and added bits of ripped up cardboard before filling the bag. The moisture level seemed right and I added the worms as well as sprinkle of worm chow, egg shells grit and a small hand of defrosted mushed up fruit/vegetable scraps which I covered with some soil. I then covered the bags contents with a double layer of soaked and wrung out newspaper. Weirdly the top layer (like 1-2 bandwidth deep) feels rather dry and there is no condensation on the inside lid/walls. squeezing a handful of solid doesn’t indicate much moisture at all, no drop coming out. However, if I but putting my hand inside the hole of the bottom of the bag it is rather wet. I understand that the worms are likely to all come to the bottom because it is wetter and I am ending up with loads of worms sneaking through the Velcro and the gaps of the bottom attachment. The bottom attachment is only slightly moist, no water is dripping. I just don‘t seem to be able to close up the bottom enough to stop the escapes. I now opened up the bottom to shove some newspaper up the hole to soak up extra moisture and hopefully created a bit more of a barrier for them to sneak through. I did spray the top a bit with water initially as I feel the worms are not keen on the dry environment but now think physics will just cause to bottom to get even wetter. The very moist newspaper on top is unlikely to soak up any of the moisture. At the moment the bottom bag is not attached to increase ventilation and to stop the worms getting caught in the Velcro. I will not feed for a week or until I am sure all food has been eaten first. Should I take some of the wet soil out from the bottom and add it to the top layer (which feels dry again but I’m hesitant to spray again) to even the moisture levels out? Do I just need to give it time for the moisture levels to balance out or am I doing something wrong? I‘m worried About the continuous large numbers from the bottom. I added the worms 3 days ago. Thanks! Rika

    1. Hi Rika! Firstly, thanks so much for getting the Urban Worm Bag! The issue you’re describing is not common, but it it’s not rare either.
      This issue will subside as the moisture stabilizes a bit. And yes, I would take some of the wetter material in the bottom (which will have plenty of worms) and put it back into the top.
      This is counterintuitive too, but I would leave the bottom off of the UWB and possibly even run a fan underneath the fabric to help dry out the material inside to help “push” the worms away from the bottom.

  8. Hi Steve,

    I’m pretty frantic about my worms escaping TWICE now in two straight days.
    Here’s the story :

    First bin is in our living room and we just started experiencing cold weather inside our house (nights can drop to 15 C and days are around 17-19 C). Not much else has changed.
    I thought the bin was too saturated because I did a couple very moist feedings and food was left over during the week. In the morning of the escape worms are all over the floor and some 5 feet away from the bin. I panicked and started a NEW coco coir mix in a separate bin and gathering and placing worms in there. Original coco soil was wet but not dripping with leftover blended green food. NEXT DAY, worms are escaping the new soil which is less moist! When I place light over bin they go back down.
    What am I doing wrong and what can I change???

    1. I’m not 100% sure Ashley but I have the following questions comments:
      –Are either of these bins new or recently established? New bins are notorious for wandering worms
      –Do you have any new sources of vibrations nearby? Worms hate vibration and will “freak out” for lack of a better word.
      –Were you having or about to have any thunderstorms near your location. Indian Blue worms, often confused for red wigglers, will try to flee en masse in response to a drop in barometric pressure.

      In the meantime, I would leave both bins uncovered under a bright light to keep them in there for a few days.

      1. I started the bin this summer/2022.
        I’ve never had escapees until now. The bin has always been in the same living room with no vibrations. The only major changes is cooling house and possibly moisture.
        I have a light over the bin now but still baffled as to what caused their unhappiness.

        I tried to email pictures of the bin so I could give a better idea of situation, but the email on your site was rejected.

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